Deployable ramp assembly

Abstract

A deployable ramp assembly including a fixed ramp portion and a pivotable ramp portion connected thereto through a direct pivot connection to pivot between stowed and deployed positions defined at a first angle from one another, a cover member pivotally connected to the fixed portion to pivot between closed and opened positions defined at a second angle from one another which is substantially smaller than the first angle, a drive assembly pivoting the cover member between the closed and opened positions, and a multiplier assembly interconnecting the pivotable portion and the cover member to transfer the pivoting motion of the cover member to the pivotable portion in an amplified manner, the multiplier assembly bringing the pivotable portion in the stowed position when the cover member is in the closed position and the pivotable portion in the deployed position when the cover member is in the opened position.

1. A deployable ramp assembly comprising:
 a fixed ramp portion; 
 a pivotable ramp portion pivotally connected to the fixed ramp portion through a direct pivot connection, the pivotable ramp portion being pivotable about the direct pivot connection between stowed and deployed positions with a first angle being defined between the pivotable ramp portion in the stowed position and the pivotable ramp portion in the deployed position, the pivotable ramp portion in the deployed position and the fixed ramp portion together defining a ramp surface, the pivotable ramp portion in the stowed position overlaying the fixed ramp portion; 
 a cover member pivotally connected to the fixed ramp portion, the cover member being pivotable relative to the fixed ramp portion between closed and opened positions of the cover member respectively corresponding to the stowed and deployed positions of the pivotable ramp portion, a second angle smaller than the first angle being defined between the cover member in the closed position and the cover member in the opened position, the cover member in the closed position covering the direct pivot connection between the pivotable and fixed ramp portions to prevent access to interconnected ends of the ramp portions; 
 a drive assembly pivoting the cover member between the closed position and the opened position, the drive assembly having one end pivotally connected to the cover member and an opposed end pivotally connected to the fixed ramp portion at a location spaced apart from the direct pivot connection, the drive assembly having a variable effective length and being actuable to pivot the cover member between the open and closed positions; and 
 a multiplier assembly interconnecting the pivotable ramp portion and the cover member, the multiplier assembly transferring the pivoting motion of the cover member to the pivotable ramp portion such that an angular displacement of the pivotable ramp portion between the stowed and deployed positions thereof is greater than an angular displacement of the cover member between the closed and opened positions thereof. 
 
     
     
       2. The deployable ramp assembly according to  claim 1 , wherein the first angle is more than 180° and the second angle is between about 90° and about 100° . 
     
     
       3. The deployable ramp assembly according to  claim 1 , wherein a ratio between the first and second angles is approximately 2. 
     
     
       4. The deployable ramp assembly according to  claim 1 , wherein the cover member is pivotally connected to the fixed ramp portion at a location vertically or approximately vertically aligned with and below the direct pivot connection. 
     
     
       5. The deployable ramp assembly according to  claim 1 , wherein the cover member includes two parallel cover link members pivotally connected to the fixed ramp portion at a first location and pivotally connected to the drive assembly at a second location, the multiplier assembly includes two parallel multiplier link members pivotally connected to a respective one of the cover link members at a third location with the second location being defined between the first and third locations, each multiplier link member being also pivotally connected to a respective side of the pivotable ramp portion at a fourth location near the direct pivot connection, the fourth location remaining on a same side of an axis extending through the first and third locations throughout pivoting travel of the pivotable ramp portion between the stowed and deployed positions. 
     
     
       6. The deployable ramp assembly according to  claim 1 , wherein the cover member includes two parallel cover link members pivotally connected to the fixed ramp portion at a first location and pivotally connected to the drive assembly at a second location, the multiplier assembly including a sliding pin extending from each of the cover link members at a third location extending at a distance from the first location approximately twice a distance defined between the direct pivot connection and the third location when the direct pivot connection and the third location are vertically aligned, each sliding pin being slidably received in a slot defined in a respective side of the pivotable ramp portion near the direct pivot connection. 
     
     
       7. The deployable ramp assembly according to  claim 1 , wherein the drive assembly includes at least one linear actuator defining part of the effective length. 
     
     
       8. The deployable ramp assembly according to  claim 1 , wherein the drive assembly is connected to the fixed ramp portion along an underside thereof. 
     
     
       9. The deployable ramp assembly according to  claim 4 , wherein the cover member includes at least one support member rigidly extending therefrom, the pivotable ramp portion in the stowed position resting against the at least one support member. 
     
     
       10. The deployable ramp assembly as defined in  claim 1 , wherein the cover member extends transversely relative to the pivotable ramp portion. 
     
     
       11. The deployable ramp assembly as defined in  claim 10 , wherein drive assembly acts solely on the cover member to thereby displace the pivotable ramp portion between the stowed and deployed positions thereof. 
     
     
       12. A deployable ramp assembly for a vehicle, the ramp assembly comprising:
 a fixed ramp portion having a first ramp surface and opposed side members extending therefrom; 
 a pivotable ramp portion having a second ramp surface and opposed side members extending therefrom, the side members of the pivotable ramp portion being pivotally connected to the side members of the fixed ramp portion adjacent connecting ends thereof, the pivotable ramp portion being pivotable with respect to the fixed ramp portion between a stowed position and a deployed position, the first and second ramp surfaces in the deployed position defining an at least substantially continuous ramp; 
 two parallel first link members each pivotally connected to a respective one of the side members of the pivotable ramp at a first location adjacent the connecting end thereof but more distanced therefrom than the connection between the side members of the pivotable and fixed ramp portions; 
 two parallel second link members each pivotally connected to a respective one of the first link members at a second location and pivotally connected to the fixed ramp portion at a third location, the second link members being rigidly interconnected by a transverse member extending therebetween, the transverse member covering the pivot connection between the side members of the pivotable and fixed ramp portions to prevent access thereto when the pivotable ramp is in the stowed position; 
 two parallel drive members each pivotally connected to a respective one of the second link members at a fourth location intermediate the second and third locations; and 
 a variable length member having one end connected to the drive members and an opposed end pivotally connected to the fixed ramp portion, the variable length member including at least one linear actuator linearly varying a distance between the opposed ends thereof such as to pivot the pivotable ramp portion between the stowed and deployed positions. 
 
     
     
       13. The deployable ramp assembly according to  claim 12 , wherein the third location is vertically aligned or approximately vertically aligned with the connection between the side members of the pivotable and fixed ramp portions. 
     
     
       14. The deployable ramp assembly according to  claim 12 , wherein an angle of rotation of the second link members with respect to the fixed ramp portion is smaller than an angle of a corresponding rotation of the pivotable ramp portion with respect to the fixed ramp portion, the first link members transferring and amplifying each rotation of the second link members to the pivotable ramp portion. 
     
     
       15. The deployable ramp assembly according to  claim 14 , wherein the pivotable ramp portion has a travel of over 180° between the stowed and the deployed positions, and the second link members have a travel of between about 90° and 100° between the stowed and deployed positions of the pivotable ramp portions. 
     
     
       16. The deployable ramp assembly according to  claim 12 , wherein throughout the pivoting of the pivotable ramp portion between the stowed and deployed positions, a first pivot axis defined at the first location remains on a same side of a plane containing a second pivot axis defined at the second location and a third pivot axis defined at the third location. 
     
     
       17. The deployable ramp assembly according to  claim 12 , wherein the transverse member is pivotally connected to the fixed ramp portion to pivot about an axis extending through the third location. 
     
     
       18. The deployable ramp assembly according to  claim 14 , wherein the transverse cover member includes at least one support member extending therefrom, the pivotable ramp portion in the stowed position overlaying the fixed ramp portion and resting against the at least one support member. 
     
     
       19. The deployable ramp assembly according to  claim 12 , wherein the drive members are rigidly interconnected by a transverse member extending therebetween, and the variable length member includes a single linear actuator rigidly connected to the transverse member and pivotally connected to the fixed ramp portion. 
     
     
       20. The deployable ramp assembly according to  claim 12 , wherein the variable length member is connected to the fixed ramp portion along an underside thereof.